Thanks, Brian.
As for the drawing ability... just a lifetime of practice and relentless drive (sometimes to the detriment of a real life, mostly out of fear of having to work for a living

) Actually it has involved many many nights of burning the midnight oil... I guess it is work, but you gotta love it.
The imagination?... A mix of insanity + being an only child entertaining himself + growing up on a farm and great uncles with outlandish stories + Mad Magazine = compulsive doodler. "Looking Up" was originally born as a sketch on a napkin while engaged in something incredibly boring. This habit drove some of my teachers to total exasperation.